Open socket wrench having oscillatable pawl



y 8, 1952 s. s. JOHNS 2,602,362

OPEN SOCKET WRENCH HAVING OSCILLATABLE PAWL.

Filed Oct. 28, 1949 INVENTOR. STANLEY $.JOHNS ATTORNEYS Patented July 8,1952 OPEN SOCKET WRENCH HAVING OSCILLATABLE PAWL Stanley S. Johns,Baltimore, Md.

Application October 28, 1949, Serial No. 124,134 6 Claims. (01. s1 92)The present invention relates to open socket wrench having oscillata-blepawl and has for its object and purpose to provide a thin, compact andcomparatively inexpensive ratchet wrench applicable to nuts and boltshaving square or hexagonal cross-sections.

A further object of the invention is to provide a ratchet wrench whichwill be eilicient in operation and of a rugged construction well adaptedto the character of the 'work'it is called upon to perform incident tothe tightening of nuts and bolts and the dislodging of the same fromtightened positions.

An important feature of this invention resides in the provision of aspring pressed pawl, which has a trunnion portion rockably fitted in abore in the wrench body and has a shank portion adapted to project intoan arcuate nut-receiving space in the wrenchjbody, the shank portionterminating in a flat nut-contacting face engageable with a flat face ofa nut. The nut-contacting face lies out'side of a plane containing theaxis of oscillation of the trunnion portion and the center of thenut-receiving space, when a stop on the wrench body is engaged by thepawl to arrest the pawl at the time when the nut-contacting face is inplanar contact with the nut.

With the foregoing and other objects in view, the invention will bevmore fully described hereinafter, and will be more particularly pointedout in the claims appended hereto.

In the drawings, wherein the symbols refer to like or correspondingparts throughout the several views,

Figure l is a perspective view of one form of socketless ratchet Wrenchconstructed in accordance with the present invention and shown over abolt head indicating the manner of initial application.

Figure 2 is a fragmentary top plan view, with parts broken away andparts shown in section, illustrating the position of the parts on thetightening stroke of the wrench which is indicated by the arrow.

Figure 3 is a similar view illustrating the backing-oif stroke of thewrench.

Figure 4 is a fragmentary bottom plan view of the Wrench shown asreversed in position for operating upon a loosening stroke.

Figure 5 is a perspective view of the pawl and its trunnion.

Figure 6 is a fragmentary perspective view showing a modified form ofthe wrench.

Figure '7 is a fragmentary top plan view, with parts broken away andparts shown in section, of the form of wrench shown in Figure 6illustrating the backing-off stroke of the wrench.

Figure 8 is a similar view illustrating the tight ening stroke of thiswrench.

Figure 9 is a bottom plan View of this wrench reversed in position andillustrating the loosening stroke of the same, and

Figure 10 is a perspective View of a form of pawl employed in thismodified form of wrench.

Referring more particularly to the drawings, the Wrench body comprises aframe or handle l5 and a head Hi. The head 16 has a part-circular innerwall H, which is preferably greater than a semicircle, and which definesa bolt head or nut receiving space being open at one side as indicatedat It.

-A pawl l9, which is of rectangular shape and having a substantiallysquared planar end surface for engaging the side face of a nut, iscarried by the head or handle and is provided with a trunnion 20 onwhich the pawl may rock. The trunnion is rotatably mounted in a bore 2|in the head or handle, which bore is somewhat greater than a semicirclein order to prevent the escape of the trunnion out through theperipherally open side of such bore 2|. The bore 2| is freely openedthrough top and bottom faces of the wrench body. In fact the order ofassembly is to introduce the trunnion axially into the bore 2!. A stop22 onthe wrench body is positioned to engage the inner side of the pawl[9 to limit its inwardly swinging or hinging movement. A shoulder 23between the pawl I 9 and its trunnion 20 at the outer side of the sameis designed to engage a stop 25 formed. at the other side of theperipheral gap of the bore 2!. The pawl l9 may rock back and forthbetween the stops Hand 24 on the axis of the trunnion 20 which is normalto the planes of the upper and lower faces of the wrench body. The pawll9 extends from the integral trunnion portion 20 in an off-centerposition relative to the center or pivoting axis of the trunnion, asbest seen in Figure 5. A notch 25 in the trunnion 20 receives a pin26"which is mounted to reciprocate in a hole 21 in the wrench body. Acoil or other spring 28 also mounted in the hole behind the pin 25 loadsthe pin with a spring bias yieldingly urging the pawl [9 against thestop 22. This is due to the fact that the pin 26 engages an end wall 30of the notch 25 which is eccentric tothe trunnion 20 on the sideopposite the stop 22.' The side wall 3! of the notch 25 is adapted tosnugly engage the side of the pin 26 when the pawl is in its normalposition against the stop 22 as shown in Figure 2. This constitutes afurther stop limiting pawl movement toward initial position. As shown inFigures 2 and 3 the pin 26 is positioned across the dividing linebetween the bore 2| and the Wrench body so that it performs the secondfunction with the notch 25 of retaining the trunnion 20 in the bore 2|and preventing the escape of the pawl from the wrench body. The load ofthe spring 28 is controlled by a screw plug 29 which incidentally closesthe outer end of the hole 21 after the pin 26 and spring 28 have beenintroduced into the same.

In operation, the wrench is applied to a nut or bolt head 32 asindicated in Figure 1 in which the open space in the head of the wrenchis poised above the nut or bolt head 32 before lowering such head uponthe bolt head or nut 32 to cause the same to be enveloped by the head inthe manner indicated in Figures 2 and 3. In thus applying the wrench tothe nut or bolt the latter is not only received into the internal spaceof the nut head but one flat side of the nut or bolt head 32 ispresented against the outer free end, or planar surface, of the pawl IIIwhich pro jects into the circle of the wall I! at the open side l8. Thiscondition is shown in Figure 2 in which the edges or corner portionsbetween facets of the nut or bolt head 32 engage with the wall I! sothat the nut-or bolt head may be maintained by the wrench head l6 upagainst the pawl I9. By rotating the wrench body in the direction of thearrow shown in Figure 2 the nut or bolt may be tightened because therotation has a tendency to keep the pawl I9 against the stop 22 and thusthe nut or bolt head will be entrained to rotate with the rotarymovement of the wrench. After an appropriate angular stroke has beenmade, the

stroke is reversed in rotation as indicated in Figure 3 in which eventthe high point or corner of the nut or bolt head 32 will force the pawl19 backwardly, compressing the spring 28 and possibly moving the pawl toa position where its shoulder 23 approaches or actually engages theouter stop 24. In any event the pawl I9 will have sufllcient freedom ofmovement due to its offcenter position relative to the axis of thetrunnion to escape past such high point or corner so that the outer endof the pawl I9 may be brought into engagement with an adjacent straightface of the nut or bolt head 32 whereby the clockwise movement of Figure2 may be repeated to advance the nut or bolt head through a subsequentturning tightening movement. After the pawl has passed the high point orcorner the coil spring 28 will re-assert itself and through the pin 26restore the pawl I'9 against the stop 22. By rocking the wrench back andforth in a well understood manner the nut or bolt 32 may be rotated stepby step toward a tightening condition.

As seen in Figures 2 and 4 of the drawing, the outer or free end of theextended portion of the pawl is cut at an angle slightly less than 90 inrelation to a line passing through the axis of rotation of the integraltrunnion and the center of the nut receiving space ll. Thus, the outeror nut engaging end of the pawl is not cut perpendicular to thelongitudinal axis of the rectangular extended portion of the pawl but iscut. at an angle of less than 90 to provide greater rotary movement ofthe nut or bolt in a loosen-- ing sense or direction; and the clockwiserotation of the wrench will simply cause the pawl I9 to click over thehigh point or corner of the nut or bolt head without entraining thelatter to move with the wrench.

It will be noted, with respect to Figures 2, 4 and 8 of the drawings,that the flat nut contacting face on the free end of the shank portionof the pawl is disposed outside of a plane, which passes through theaxis of oscillation of the trunnion portion 20 and the center of thenutreceiving space. The nut-contacting face lies outside of the plane,the outside meaning to the side of the plane in which the pawl portionswings, as seen in Figures 3 and '7. The shank portion swings away fromthe plane, as the pawl swings towards the stop 24 in the clockwiserotation of the wrench. As seen in the drawings, the plane also containsthe planar stop wall but, such form of stop is not critical, since anystop arrangement can be used, such as a stop carried by the trunnionportion. The construction and characteristics of the stop elements arenot critical except that such stop elements must act to arrest inwardmotion of the pawl relative to the nut-receiving space or the abovedefined plane at a point which will prevent the innermost edge of thenut-contacting face from passing inwardly or over the plane. Thus, thenut-contacting face of the pawl must not extend inwardly. of the planecontaining the axis of rotation of the trunnion portion and the centerof the nut-receiving space of the wrench body.

Referring more particularly to the second form of the invention shown inFigures 6 to 10 inclusive, all parts are substantially the same and aresimilarly referenced with the following diiTerences. The wrench head I6has a completely closed wall Il In other words Figure 1 shows an openend style of wrench and Figure Gshows, a closed end type somewhat alongthe lines of a conventional box wrench.

Inasmuch asthere is no open end wall such as 24 in Figure 1, theshoulder 23 of the pawl I9 is omitted and the outer Wall l9 merges fromthe same plane throughout into the rounded adjacent peripheral wall ofthe trunnion 20*. This wall I9 is adapted to engage against a diagonalwall 33 in the wrench body spaced from the stop 22 to afford a spacewider than the pawl II! in which the pawl IS! may have latitude to moveback and forth.

Although I have disclosed herein the best. form of the invention knownto me at this time, I reserve the right to all suchmodifications andchanges as may come within the scope of the following claims.

What I claim is:

1. A wrench for ratcheting on a nut, said wrench comprising a wrenchbody having an arcuate nut-receiving space, and a spring pressed pawlrockably carried by the wrench body and comprising a shank portion and apartially cylindrical trunnion portion, said trunnion portion beingfitted in a complementary partially cylindrical bore in said wrench bodyso as to be oscillatable about the axis of the bore, said shank portionhaving a fiat nut-contacting face projecting into said arcuatenut-receiving space to engage a fiat face of a nut, the peripheral wallof said partially cylindrical bore being spaced from said arcuatenut-receiving space, a stop on the wrench body engaged by the pawl toarrest the pawl when the fiat nut-contacting face is in planar contactwith the flat face of the nut, said nut-contacting face when said pawlis arrested by the stop lying outside of a plane containing the axis ofoscillation of said trunnion portion and the center of said arcuatenut-receiving space, said arcuate nut-receiving space being of suchdimensions that the wrench body will contact at least those corners ofthe nut lying opposite the fiat face of the nut so as tomaintain the nutagainst the pawl.

2. The combination of claim 1, wherein means is provided to retain thetrunnion portion in the bore while permitting its oscillatory movement,said last means including a pin positioned across the dividing linelbetween the bore and wrench body and entering a notch in the trunnionportion larger than the pin.

3. The combination of claim 2, wherein the spring pressed pawl isprovided with a biasing means including a spring acting directly uponsaid pin to exert a potential rotational movement on the trunnionportion in a direction to shift the shank portion against the stop wall.

4. The combination of claim 1, wherein means is provided for biasing thepawl portion to one side of the nut-receiving space and means isprovided for retaining the trunnion portion in the bore while permittingits oscillatory movement therein, said last two means being combined ina single structure including a spring projected pin extending across thejoint between the wrench body and the trunnion and exertin thrustagainst an end wall of an eccentric notch in the trunnion portion, saidnotch also having a side wall for engaging the side of the pin when thepin is in projected position.

5. The combination of claim 1, wherein the nutreceiving space is open atone side adjacent the pawl.

6. The combination of claim 1, wherein the nut-receiving space is boxedin on all sides.

STANLEY s. JOHNS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

